sphenoid vs sphenoid bone

sphenoid

noun
  • The sphenoid bone. 

  • A wedge-shaped crystal bounded by four equal isosceles triangles; the hemihedral form of a square pyramid. 

adj
  • Having a wedged shape. 

  • Of or relating to the sphenoid bone which forms the base of the cranium, behind the eye and below the front part of the brain. It has two pairs of broad lateral ‘wings’ and a number of other projections, and contains two air-filled sinuses. 

sphenoid bone

noun
  • A compound bone at the base of the skull behind the eyes. 

How often have the words sphenoid and sphenoid bone occurred in a corpus of books? (source: Google Ngram Viewer )